Clinical and morphologic evolution of idiopathic membranous nephropathy

Twenty-five adult patients with idiopathic membranous nephropathy (IMN) and nephrotic syndrome (NS) who had participated at a long-term randomized trial with steroid and chlorambucil for six months, underwent repeated renal biopsies. The mean interval between pretreatment and the second biopsy was 41 months. Five evolutionary morphologic changes were adopted. Extensive normalization of the basement membrane (stage V) was observed in 6 of the 9 patients with complete and sustained remission. Only patients in stages I or II at admission seemed to get to reparation stage V. Persistence of NS or a partial remission was usually associated to the progression of the capillary wall lesion to stage III or IV. Our treatment schedule significantly increased the likelihood of getting to the reparation stage V.